First a word of caution: Don't use the bleeding edge perl releases
unless you're willing to experiment with a potentially highly unstable
perl release. They're generally only useful for Perl 5 porters or anyone
interested in watching their work.
Jarkko Hietaniemi publishes the latest perl development snapshots
on an FTP server in Finland, whenever they're ready. This script
will connect to this server, select the latest release and download its
compressed tar file.